Libinfo in Apple Mac OS X before 10.6.7 does not properly handle an unspecified integer field in an NFS RPC packet, which allows remote attackers to cause a denial of service (lockd, statd, mountd, or portmap outage) via a crafted packet, related to an "integer truncation issue."
http://support.apple.com/kb/HT4581
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html